Pool Pump Conversion

From above to below

The primary differences between brushed motor pool pumps and variable speed electronic versions lie in their control mechanisms and motor designs. Variable speed pumps offer advanced electronic controls for precise speed adjustment, leading to energy savings and improved performance. Their motor design, often brushless, reduces maintenance, increases efficiency, and extends the pump’s lifespan. In contrast, brushed motors are simpler and might be less expensive initially but could lead to higher operational costs and maintenance over time due to their inherent design limitations.

When comparing a brushed motor pool pump to a variable speed electronic version, it’s essential to consider both the electronic control differences and motor design differences, as these aspects fundamentally influence their efficiency, durability, performance, and maintenance requirements. Let’s delve into these distinctions to provide a comprehensive understanding.

1. Electronic Control Differences

Brushed Motor Pool Pump

• Speed Control: Brushed motors generally operate at a fixed speed, determined by the line frequency and the construction of the motor. Speed control, if available, is less sophisticated, often achieved by adjusting voltage or using resistive or capacitive methods, which can be inefficient.
• Control Mechanism: The control system for brushed motors is relatively simple, typically involving manual switches or basic electromechanical relays for starting and stopping.

Variable Speed Electronic Version

• Speed Control: Variable speed drives (VSDs) or inverter drives control these motors. This technology allows for precise speed control over a wide range, optimizing the pump’s performance to the pool’s needs, leading to significant energy savings.
• Control Mechanism: These pumps use advanced electronic controls, such as digital signal processors (DSPs), that can adjust the motor’s speed and torque in real-time. This capability enables features like programmable schedules, remote monitoring, and integration with smart home systems.

2. Motor Design Differences

Brushed Motor Pool Pump

• Construction: Brushed motors contain carbon brushes and a commutator that make physical contact with the spinning armature, creating electrical connections that power the motor. This design is simpler but prone to wear and tear over time.
• Maintenance: The brushes and commutator experience wear, requiring regular inspection and replacement, which adds to the maintenance cost and downtime.

Variable Speed Electronic Version

• Construction: Variable speed pumps typically use brushless DC motors (BLDC) or permanent magnet synchronous motors (PMSM). These designs eliminate the need for brushes, using electronic commutation to control the motor’s magnetic field and rotation.
• Efficiency and Longevity: Without the mechanical contact points of brushes, these motors are more efficient, generate less heat, and have a longer lifespan. The lack of brushes reduces maintenance needs and improves reliability.

Design of BLDC Motor Pool Pump Controller

1. Electronic Commutation System

• BLDC motors are electronically commutated, unlike their brushed counterparts that use physical brushes for commutation. The controller uses solid-state electronics to switch the current in the motor windings, synchronizing the electrical and mechanical rotations of the motor.
• This system involves Hall effect sensors or rotor position sensors that provide feedback on the rotor’s position, ensuring precise timing of current switching to the motor windings for optimal efficiency.

2. Speed and Torque Control

• The controller adjusts the motor speed by varying the power supply’s voltage or employing pulse-width modulation (PWM). PWM controls the motor’s speed by rapidly turning the power to the coils on and off, allowing for precise speed control without sacrificing torque.
• Advanced controllers may implement sensorless control techniques, relying on back-EMF (ElectroMotive Force) signals from the motor to determine the rotor position, eliminating the need for physical sensors.

3. Programmable Features

• Many BLDC pool pump controllers come with user-friendly interfaces for programming operational schedules, speed settings for different tasks (e.g., filtration, heating, or cleaning), and diagnostic tools for maintenance alerts.
• Integration capabilities with home automation systems for remote control and monitoring are increasingly common, enhancing the user experience.

4. Protective Features

• They often include various protective features to extend the motor’s life and ensure safe operation, such as over-current protection, thermal overload protection, and under-voltage / over-voltage protection.

A BLDC is essentially a synchronous AC motor

Fundamentals of BLDC Motors

A BLDC motor operates on direct current (DC) electrical power, but its operation mimics that of a synchronous alternating current (AC) motor due to how its internal mechanisms are designed and controlled.

Electronic Commutation

• Unlike brushed DC motors, which mechanically switch the current direction in the motor using brushes and a commutator, BLDC motors use electronic commutation. This electronic commutation changes the phase of the current in the motor windings to keep the motor turning.
• The switching of the current is synchronized with the position of the rotor to ensure that the magnetic fields generated by the stator windings rotate in step with the rotor, a characteristic feature of synchronous motors.

Similarity to Synchronous AC Motors

Synchronous Operation

• Both BLDC motors and synchronous AC motors operate in a synchronized manner, where the rotation of the rotor is in sync with the frequency of the supply current. In the case of BLDC motors, the electronic controller adjusts the timing of the current in the windings to maintain this synchronization, similar to how the AC supply frequency dictates the operation of an AC synchronous motor.

Use of Permanent Magnets

• Many synchronous AC motors and BLDC motors use permanent magnets in their rotor design. This similarity helps create a consistent magnetic field that interacts with the alternating current in the stator windings to produce a rotating magnetic field, driving the rotor.

Distinctions from Traditional AC Motors

Despite these similarities, it’s crucial to distinguish BLDC motors from traditional synchronous AC motors in terms of power supply and control methods.

• Power Supply: BLDC motors are designed to run on DC power, using a controller to simulate an AC-like effect within the motor. In contrast, synchronous AC motors are designed to run directly on AC power.
• Control Complexity: BLDC motors require an electronic controller to manage the timing of the current in the motor windings, making their control systems more complex than those of traditional synchronous AC motors, which can run directly off the AC grid with the appropriate starting mechanism.

a BLDC motor is considered similar to a synchronous AC motor because both types of motors maintain synchronization between the rotor and the magnetic field produced by the stator. However, the BLDC motor achieves this through electronic commutation using DC power, while the synchronous AC motor uses AC power directly. This fundamental approach to achieving synchronous operation highlights the innovative blend of AC motor principles with DC power and electronic control in BLDC motor design.

An electronically commutated motor is a synchronous motor, that can be excited as a direct current motor via inverter electronics. Inverter electronics is a type of power electronic device that converts direct current (DC) to alternating current (AC). It is also known as an EC motor or, as it does not have brushes like conventional direct current motors, which cause high-frequency interference in the supply mains, a BLDC motor (“brushless direct current”). PM motor (“permanent magnet”), is a further designation and refers to the fact that the rotor is a permanent magnet. The stator comprises several magnet coils and has a three-phase design Commutation is effected electronically via the three coil strands and a bridge circuit.

The rotational speed of EC motors can be easily changed, making them ideal for controlling the speed of centrifugal pumps. They also have high output per size and very good efficiency, and exhibit no slip or heat build-up.

New modern pump parts

TEFC motor. A Totally Enclosed, Fan-Cooled ( TEFC) electric motor is a type of industrial electric motor with an enclosure that does not permit outside air to freely circulate through the interior of the motor.

It’s becoming evident if your doing a motor replacement for an existing unit the price is very high and not including the electronic control

To be continued, what needs to be identified is a less expensive motor and possibly a VFD to drive it. 2hp VFD are in the $100 range

The conditions for installing in the wet environment are an important consideration. The pentair control box is 250 bucks and the motor over 600. At these prices it might be abetter decision to just purchase a complete unit. The prices are very high all starting over 1000 bucks.

What are objective is or it was to keep our pump head which is perfect and update to varible speed brushless high efficiency motor

Getting closer to identifying a ready configured motor we have identified the flange as 56Y